Method and device for unwinding elongated stock

ABSTRACT

An elongate product (BA 1 ) is transported away from its storage device (VT) in such a way that at least one loop (SL) is formed at at least one longitudinal point on its running path (AW 2 ). Changes in the geometric shape of the loop (SL) are registered and used to control or regulate the outward transport movement of the elongate product (BA 1 ).

FIELD OF THE INVENTION

The invention relates to a method of unwinding an elongate product froma storage device, on which the product is stored with a large number ofturns.

BACKGROUND OF THE INVENTION

EP 0 182 981 discloses an apparatus in which an optical waveguide ishauled off a driven, rotating plate over a pivotably suspended lever anda following, freely rotatable deflection roller. In this case, thedeflection roller is located in a plane perpendicular to the face of theplate. Its running face runs tang tangentially to the windings of theoptical waveguide on the plate. At its end adjacent to the plate, thelever has an eye to guide the optical waveguide. Because of its abilityto pivot parallel to the haul-off plane of the optical waveguide, it isable to follow the wandering of the optical waveguide, within certainlimits, as said waveguide changes from one winding path to the next. Asa result of the lever pivoting outward, a transmitter, such as apotentiometer, is actuated and influences the rotational speed of theplate in such a way that the lever returns to its central position.Satisfactory unwinding or hauling-off of the optical waveguide stored inthis way from the plate for subsequent further processing steps can bemade more difficult in practice. In particular, there is the danger thatthe optical waveguide hauled off the plate is loaded with animpermissibly high tensile stress.

BRIEF SUMMARY OF THE INVENTION

The invention is based on the object of indicating a way in which anelongate product can be unwound satisfactorily in a straightforwardmanner from its storage device. According to the invention, in a methodof the type mentioned at the beginning, this object is achieved in thatthe elongate product is transported away in the axial direction from thestorage device in such a way that at least one loop is formed at atleast one longitudinal point on its longitudinal outward transport path,that changes in the geometric shape of the loop are registered, and thatthese changes are used to derive at least one control criterion for theoutward transport movement of the elongate product.

The fact that at least one loop is formed for the elongate product alongits longitudinal haul-off path, after it has been transported away fromits storage device, and changes in the geometric shape of this loop areregistered and used to derive at least one control criterion for theoutward transport movement of the elongate product means that theelongate product can be unwound from its storage device satisfactorilyunder a large number of practical conditions.

This principle according to the invention is preferably suitable forunwinding telecommunication cable elements, in particular opticaltransmission elements, preferably optical waveguide cable, from supplycoils or supply plates.

The invention further relates to an apparatus for unwinding an elongateproduct from its storage device, on which the product is stored with alarge number of turns, which is characterized in that outward transportmeans for transporting the elongate product away from its storage devicein the axial direction are provided in such a way that at least one loopof the product can be formed at at least one longitudinal point in itslongitudinal outward transport path, in that a measuring device forregistering changes in the geometric shape of the loop is provided, andin that this measuring device is assigned a control device which usesthese changes to derive at least one control criterion for the outwardtransport movement of the elongate product.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows, schematically in a perspective illustration, an exemplaryembodiment of an unwinding apparatus for unwinding an elongatetelecommunication cable element from a supply coil in accordance withthe invention,

FIG. 2 shows, in a schematic side view, the unwinding apparatus of FIG.1 together with a downstream stranding device, to which the unwoundtelecommunication cable element is fed, and

FIG. 3 shows, schematically in perspective illustration, an exemplaryembodiment of an unwinding apparatus for unwinding an elongatetelecommunication cable element from a plate in accordance with theinvention.

Elements with the same function and mode of action are in each caseprovided with the same reference symbols in FIGS. 1 to 3.

FIG. 1 shows, schematically in a perspective illustration, an unwindingapparatus AV which operates on the principle according to the invention.Its components are arranged on a largely flat baseplate BP. Thisbaseplate BP is also shown in FIG. 1, in particular as representative ofthe floor of a factory hall.

DETAILED DESCRIPTION OF THE INVENTION

The unwinding apparatus AV has a supply coil or supply drum VT, on whoseapproximately circularly cylindrical coil former SK an optical cableBA1, in particular an optical-waveguide bundle tube, is stored aselongate product with a large number of turns. The coil former SK is inthis case bounded in the axial direction (as referred to its centralaxis) by a circular disk-like side flange SF1, SF2 at each of its twoends. In this way, along the longitudinal extent of the coil former SK,a laterally enclosed storage area for the turns of the optical waveguidecable BA1 is formed. As a result, individual turns of the opticalwaveguide cable BA1 are largely prevented from falling off the coilformer SK. The supply coil VT is rotatably mounted on a rotary axle orrotary shaft DW. This rotary shaft DW is preferably constructed as acircularly cylindrical rod. It extends essentially parallel to the flatbaseplate BP. At one end, the rotary shaft DW is rotatably mounted in abearing block LB1. Its other end projects freely outward. As a result,an empty supply coil can simply be pushed off the rotary shaft DW inorder to be changed, and a new full coil can be pushed onto said shaft.In order to unwind the optical waveguide cable BA1, the supply spool VTis preferably firmly seated on the rotary shaft DW. It can, inparticular, be releasably locked on the rotary shaft DW in both theaxial and the circumferential direction.

For the purpose of driving the supply coil VT in rotation, the rotaryshaft DW is operatively connected to a drive device MO1, in particular amotor. In this case, in FIG. 1 the rotational movement of the supplycoil VT effected by the motor is indicated by a rotation arrow R1. Thedrive device MO1 has, in FIG. 1, a rotating drive shaft ZS, inparticular a toothed-belt pulley. Its direction of rotation is indicatedby a rotation arrow R1*. The drive shaft ZW extends essentially parallelto the rotary shaft DW of the supply coil VT. It is in particularassociated with the free end of the rotary shaft DW. In the area of thefree end of the rotationally driven drive shaft ZS and of the rotaryshaft DW, a toothed belt ZR runs around endlessly. This toothed belt ZRis seated on a partial circumference of the rotary shaft DW, and isfirmly tensioned over a partial circumference of the drive shaft ZS.

The drive device MO1 is driven by a control device SE via a control lineSL1. In particular, this permits the setting of the rotational speedand/or torque which is exerted by the drive device MO1 on the supplycoil VT in a desired manner by the control device SE.

With the aid of the drive device MO1, it is expediently possible notonly to exert a driving effect but, in addition, or independently ofthis, also a braking effect on the supply coil VT.

The optical waveguide cable BA1 is stored with a large number ofapproximately circularly annular turns on the outer surface of thecircularly cylindrical storage element SK. Along the longitudinal extentof the storage element SK, these turns in each winding layer are to afirst approximation arranged parallel and beside one another. In thisway, an essentially circularly cylindrical winding pack of the opticalwaveguide cable BA1 is kept as a supply on the supply coil VT.

From this rotationally driven winding pack, the optical waveguide cableBA1 is hauled off or transported away along its axial longitudinalextent with the aid of a downstream haul-off device RA1, in particular acaterpillar-belt haul-off. The longitudinal outward transport movementof the bundle tube BA1 is indicated by an arrow AZ in FIG. 1. In FIG. 1,the longitudinal haul-off path AW1 of the optical waveguide cable BA1runs, by way of example and to a first approximation, linearly and in aplane which is preferably located essentially parallel to the baseplateBP. For this purpose, the optical waveguide cable BA1 is hauled offapproximately at the 12 o'clock position, that is to say from the upperside of the winding pack, and is fed to the haul-off device RA1 at anapproximately constant height above the floor BP. The haul-off deviceRA1 is permanently fitted in an elevated manner to a frame LB3. Duringthe unwinding operation of the optical waveguide cable, a constanttorque is preferably set for said haul-off device. It is used as anauxiliary haul-off to haul off the cable from the supply coil VT undertension.

As viewed in the haul-off direction AZ, the optical waveguide cable BA1downstream of the haul-off device RA1 is paid out from its originallongitudinal haul-off path AW1, here in the exemplary embodimentextending rectilinearly, with the aid of a following guide device FV, toform a single loop SL. For this purpose, the guide device FV has anumber of preferably rotatably mounted deflection rollers RO1 to RO4 ona frame or bearing block LB2. These deflection rollers RO1 to RO4 arepreferably designed to be essentially circularly cylindrical. They eachextend transversely, that is to say laterally, in particularperpendicularly, to the axial haul-off path AW1 of the optical waveguidecable BA1. The optical waveguide cable BA1 coming from the haul-offdevice RA1 is initially led over the first deflection roller RO1 on theinput side of the guide device FV and then led through between a pair ofrollers RO2/RO3 and, in the process, deflected from its original, axialhaul-off path AW1. The pair of rollers RO2/RO3 is formed by twocircularly cylindrical deflection rollers which are fitted parallel andone above another. The intermediate spacing from each other isexpediently selected to be approximately equal to the external diameterof the optical waveguide cable BA1, so that, in the lateral direction asreferred to its axial haul-off path, said cable is guided and fixed inposition to a certain extent. From this pair of rollers RO2/RO3 (asreferred to the horizontal, flat floor BP), the cable BA1 hangs down soas to be freely mobile in the vertical direction. It is bent aroundthrough approximately 360° from its original outward transport direction(downstream of the haul-off device RA1) and led through between the twoguide rollers RO2/RO3 again, in order then, downstream of the loop SL,to follow a new, axial outward transport path or running path AW2. Inthis case, the lower guide roller RO3 acts in the manner of a transversebeam on which the cable BA1 rests. It hangs down from this transversebeam as a result of its own weight so as to be freely mobile essentiallyin the form of a circular ring. The cable BA1 is therefore paid out inthe form of a loop or sling, which is suspended on the lower deflectionroller RO3 such that it hangs down freely. From the pair of deflectionrollers RO2/RO3, the optical waveguide cable BA1 is fed to thedeflection roller RO4 on the output side and laid on the latter at thetop. The cable BA1, starting from this deflection roller RO4, is thenfed along the axial longitudinal outward transport path AW2, which herein the exemplary embodiment likewise runs essentially rectilinearly, toat least one following further processing device. The latter has beenleft out of FIG. 1 to ensure clarity of the drawing.

If necessary, it may even be sufficient to provide only one singledeflection roller, such as RO3, for the vertical suspension of the loopSL. In particular, it may be expedient to provide only the deflectionrollers RO1, RO4 or only the pair of rollers RO2/RO3. In particular, itmay also be sufficient to fit the respective deflection roller to theframe LB2 such that it is stationary, that is to say not rotatablymounted.

In addition, it may possibly be expedient to pay out the respective loopof the optical waveguide cable BA1 not vertically but essentiallyhorizontally (as referred to the floor BP), for example on a flat plate,where the geometric shape of the loop can be established so as to befreely mobile. It is then possible for the deflection rollersadvantageously to be dispensed with entirely.

Considered in summary, therefore, the optical waveguide cable BA1 istransported away from its supply coil VT in such a way that at least onefreely mobile loop SL is formed at at least one longitudinal point onits axial longitudinal outward transport path. In particular, it mayalso be expedient to pay out a number of loops approximately paralleland beside one another in the lateral direction, as viewed withreference to the longitudinal outward transportpt path. In particular,loop of the cable can also be provided at a number of successivelongitudinal points on the axial cable outward transport path.

The loop SL is advantageously paid out with approximately the samedirection of curvature with which the optical waveguide cable BA1 waswound on the supply coil VT. The direction of curvature of the loop SLis indicated in FIG. 1 by a rotation arrow R2. This rotation arrow R2runs in the same direction of rotation as the rotation arrow R1 for therotationally driven supply coil VT. If, for example, the cable BA1 waswound onto the supply coil VT with turns in the clockwise direction,that is to say with right-hand turns, then it is expediently also bentaround in the clockwise direction, out of its original, axial haul-offpath AW1, to form the loop SL. As a result, alternating bending of thecable BA1 is largely avoided.

The cable BA1 is therefore not bent counter to its original windingcurvature when paying out the loop, which in practice would possiblyrequire the use of impermissibly high bending forces and could lead toimpermissibly high stressing of the optical waveguide cable. Bymaintaining the direction of curvature of the cable, with which thelatter was wound onto its supply coil, the cable BA1 is laid virtuallyautomatically to form the loop SL. This is because, during its storageon the supply coil VT, the cable BA1 often has a specific bendingdirection impressed on it as a result of plastic material deformation.This winding direction manifests itself in particular primarily when thecable is wound onto the supply coil immediately after the productionprocess, with the outer plastic sheath still heated. The plasticmaterial of the wire sheath, which has not yet quite cooled down andsolidified and can therefore still be deformed within certain limits,can have a curvature applied to it in or counter to the clockwisedirection, depending on the winding direction. By laying the loop SL inthis original winding direction, this can largely be paid out with a lowbending force.

This manner of laying the loop is therefore advantageously alwaysuniversally possible for a large number of elongate products havingdifferent material characteristics, cross-sectional dimensions andconstructions. If the same direction of curvature is selected for theloop as that with which the respective elongate product was wound ontoits storage device, said product can be paid out to form a loop even inthe event of a still high inherent material stiffness. In addition, verythick or very thin wound products can always be laid in a simple andunique manner to form such a loop with a circularly annularcross-sectional shape. Expressed in general terms, therefore, such aloop can always be paid out with a unique geometric shape and, with theaid of said loop, the outward transport movement of the product canalways be controlled or regulated in a precisely controllable manner.

If necessary, it may be expedient to select the external diameter of thecircularly annular loop SL to be, to a first approximation,approximately the winding diameter of the turns of the cable BA1. As aresult, additional bending forces for rebending the cable counter to itspreviously impressed winding direction when laying the loop are evenbetter avoided.

In this way, the external diameter D of the circularly annular loop SLis primarily determined by the inherent weight of the optical waveguidecable BA1and by the haul-off speed with which the cable BA1 istransported away along the outward transport path AW2 by the guidedevice FV.

This advantageously makes it possible to use changes in the geometricshape of the loop SL as a control criterion for the unwinding and/oroutward transport movement of the optical cable BA1. For this purpose,changes in the geometric shape of the loop SL are registered with theaid of a measuring sensor. In FIG. 1, a non-contact measuring sensor USis fitted to the frame LB2, underneath the loop SL paid out verticallyin relation to the baseplate BP, and at a distance from the loop SL. Inparticular, the measuring sensor US used is an ultrasonic sensor. Thismeasuring sensor US measures distance changes ΔAS of the loop SL, andtherefore, indirectly, any change in the external diameter of said loop.The measuring sensor US converts these registered distance changes ΔASof the loop SL into electrical measured signals, and sends these via themeasurement line ML to the control device SE. The control device SE thenuses the measured distance changes ΔAS of the loop SL from thenon-contact measuring sensor US as a control criterion for influencingthe outward transport movement of the opticalcable BA1 along its axiallongitudinal haul-off path AW1 and/or its outward transport path AW2. Ifnecessary, it may also be expedient, as the control criterion, tomeasure the change in the external diameter of the circularly annularloop SL directly by using a suitable measuring sensor. The changes inthe geometric shape of the loop SL are preferably measured continuouslyduring the unwinding operation and provided to the control device SE forevaluation. The control device SE then uses the measurement data pickedup to continuously derive at least one control criterion for regulatingthe outward transport movement of the cable BA1 along its haul-off pathAW1 between the supply coil VT and the haul-off device RA1 and/or alongthe transport path AW2 which follows the haul-off device RA1. Because ofthe control criterion that is obtained continuously during the unwindingoperation, it is therefore possible for the control device SE to controlthe rotational speed of the drive device MO1 continuously via thecontrol line SL1.

The control criterion derived from the measured changes in the loopgeometry is expediently used for the purpose of influencing the outwardtransport movement of the cable BA1 along its longitudinal outwardtransport path AW2 downstream of the haul-off device RA1 in such a waythat a predefined diameter D of the loop SL can always be kept largelyconstant. This makes it possible to feed the cable BA1 to a subsequentfurther processing device largely with a low tensile stress, inparticular with no tensile stress, that is to say loosely or relieved ofstress. As a result of the freely mobile, vertically hanging loop SL, inaddition any fluctuations in speed which are caused by followingmachines arranged downstream (of the haul-off device RA1), such as astranding machine, can largely be compensated for by means ofappropriate diameter changes. Disturbing influences of thesefluctuations in speed on the unwinding operation of the cable BA1 fromVT can therefore be largely avoided. In this way, high unwinding speedsof the optical cable BA1 are made possible. This is because abruptchanges in speed, which could be attributed to following processingmachines of the optical cable, are decoupled by the loop SL from theunwinding operation of the rotationally driven supply coil VT and itsdownstream auxiliary haul-off RA1. As a result, in particularimpermissibly high tensile stressing of the optical cable BA1 during itsunwinding movement from the supply coil VT, or even breaks in theoptical cable, are largely avoided. If, for example along thelongitudinal outward transport path AW2 from the haul-off device RA1 toa following further processing machine, there is a brief increase in thespeed of the cable, then the diameter D of the loop SL decreases and, asa result, compensates for the increased length of cable transportedaway. If, on the other hand, there is a brief drop in the speed of thecable along the outward transport path AW2, then the loop diameter Dincreases appropriately. As a result, along its longitudinal extent onthe outward transport path AW2, the cable always remains largely under alow tensile stress.

For an outward transport movement under the lowest possible tensilestress, the optical cable BA1 is expediently predefined an externaldiameter D for the loop SL between 20 cm and 150 mm, which is intendedalways to be maintained largely by appropriate control and/or regulationof the outward transport movement of the optical cable BA1. As long asthis external diameter or, expressed in general terms, the predefinedgeometric shape, in particular size, of the loop is largely maintainedduring the outward transport movement of the optical cable BA1 from thesupply coil VT, it is also ensured that the cable BA1 leaves the pullingdevice RA1 in a largely loose state, that is to say without beingsubject to impermissibly high tensile forces, and can therefore be fed,largely with a low tensile stress, to following further processingdevices. The haul-off force which is applied in order to transport thecable BA1 forward downstream of the haul-off device RA1 in this caseessentially corresponds only to that negligible haul-off force which isdetermined by the inherent weight of the optical cable BA1.

The loop SL is formed in particular by a single circuit, that is to saya single turn, of the optical cable BA1. If appropriate, it can also beexpedient to provide a number of such loops SL parallel, beside oneanother and laterally with respect to the longitudinal axis of the cableBA1. As a result, still more compensation length is provided in order tocompensate for speed fluctuations in following further processingmachines. If appropriate, it may also be expedient to provide suchcompensation loops at a number of longitudinal points located one afteranother on the longitudinal haul-off path of the cable BA1.

The unwinding concept according to the invention is of course suitablenot only for hauling off an optical cable, such as BA1, but also for theoutward transport of other elongate products, in particulartelecommunication cable elements, from storage devices. Thus, inpractice, for example, optical transmission elements, such as opticalwaveguide ribbons, solid optical waveguide cables, and so on are kept instore on supply coils or horizontally mounted plates, and can then behauled off or uncoiled from these for further processing. In the sameway, it may be expedient to use the unwinding concept according to theinvention for unwinding electrical telecommunication cable elements,such as electrical conductors or the like.

FIG. 2 shows a schematic longitudinal depiction of the unwindingapparatus AV of FIG. 1 with the associated control scheme, as well as astranding device SZV which is arranged downstream and to which theunwound, elongate cable BA1 is fed. The control device SE has a speedcontroller DR which is connected via the control line SL1 to the drivedevice MO1 for the supply coil VT. The drive device MO1 is assigned aso-called tachogenerator TG1, which supplies the actual speed valuecurrently reached to the speed controller DR via a feedback line SL1*.The speed controller DR then compares this actual speed with a desiredreference speed value RS which is to be set, and continuously regulatesthe drive device MO1 to this reference speed value. The fact that thedrive device MO1 is operatively connected to the rotary shaft DW of thesupply coil VT is indicated in FIG. 2 by an action arrow WP1.

As distinct from the speed regulation of the drive device MO1, a motorMO2 with associated tachogenerator TG2 is provided for the haul-offdevice RA1, for which motor a constant torque is set. As a result, thehaul-off device RA1 always exerts on the cable BA1 a tensile force suchthat the cable BA1 always remains tensioned tautly on its running pathAW1 between the supply coil VT and the haul-off device RA1. Regulationof the motor MO2 by the control device SE is not required in this case.

Using the measuring sensor US, changes in the direction ΔAS of the loopSL with respect to the measuring sensor US are measured and used as ameasure of the change in the diameter of the loop SL. Here, themeasuring sensor US is connected to the control device SE via themeasuring line ML. The measured signals ID* generated by the measuringsensor US are fed via the measuring line ML to a controller PI, inparticular a so-called proportional-integral controller. This controllerPI compares the actual measured value ID* for the loop diameter which ispicked up in each case with the predefined reference loop diameter valueD and, if necessary, generates a control signal ΔD, in order to be ableto keep constant this desired reference value D for the loop diameter bymeans of appropriate regulation of the rotational speed of the supplycoil VT. For this purpose, the controller PI transmits the appropriatelycorrected actuating signal ID*+ΔD via a line IL1 to an adder SU. As afurther input variable, this adder SU is fed via a connecting line VLwith the haul-off speed signal LW of the haul-off device SZV arrangeddownstream. This line control value, added to the corrected actuatingsignal ID*+ΔD, is fed via the line IL2 to the speed regulator DR as areference variable, which is a measure of the reference speed RS to beset.

If the haul-off speed of the cable BA1 increases because of thestranding operation of the stranding device SZV, the loop diameterdecreases. In order to reach the same loop diameter D again andtherefore as far as possible to have no tensile stress in the cable BA1along its outward transport path AW2, the control device SE increasesthe speed of the motor MO1 and therefore of the supply coil VT in such away that correspondingly more running length of the cable BA1 runs offthe supply coil VT, and the loop accumulator SL is again filled withsufficient supply length. If, conversely, the haul-off speed of thecable decreases because of the stranding operation, the loop diameter ofthe loop SL increases, which in turn is registered by the measuringsensor US. The measured signals ID* from the latter are forwarded to thecontroller PI of the control device SE. The controller PI then producesa control variable ID*+ΔD, with the aid of which the speed controller DRis instructed to reduce the speed of the supply coil VT appropriately,so that less running length of the cable BA1 runs off the supply coilVT. As a result, the accumulator length of the loop SL iscorrespondingly shortened, and therefore the original loop diameter D isreadjusted.

In this control concept, the haul-off device RA1 pushes the runninglength of the cable into the accumulator formed by the loop SL with aconstant torque. It is used only for the purpose of keeping the cableBA1 taut on its running path AW1 directly downstream of the supply coilVT, so that it cannot sag there. As a result, tangling of the cable isreliably counteracted.

The controller PI can expediently be designed in such a way that it onlyreacts when an upper limit for the change in the loop diameter isexceeded. As a result, the loop controller does not respond to veryshort speed fluctuations of the cable on its running path AW2. These aretherefore preferably compensated for solely by means of small,negligible changes in the diameter of the loop SL. Very rapid, abrupt,that is to say brief, changes in the speed of the cable are thereforepreferably not converted into changes in the speed of the supply coil VTby the controller PI in this controller concept.

In FIG. 2, the optical cable BA1, after passing through the loopaccumulator, formed here by the single loop SL, is fed to the strandingdevice SZV. This stranding device SZV is constructed in particular as anSZ stranding machine. It has an elongate, rectilinear storage elementSD, in particular a cylindrical tube, which is set rotating in oppositedirections (SZ stranding). As a result, the respective stranding elementis wrapped around the outer circumference, that is to say on the smoothsurface of the rectilinear storage element SD. The storage element SD isrotatably mounted in a stationary feed device FS. Of course, furtherbearings—not specifically illustrated here—can also be provided. Forreasons of simplicity, only the optical cable BA1 is illustrated alongthe course of the storage element SD. Of course, the same type ofwrapping applies to the other stranding elements, that is to say furtheroptical cables BA2 to BAn, which are fed to the stranding device SZV ina manner corresponding to the optical cable BA1 by unwinding devices ofsimilar construction. At the right-hand end, the output side, of thestorage element SD, a stranding disk VS is provided, and is firmlyseated there on the storage element SD. At the left-hand end, storageelement IS SD is supported by a bearing member LB4. The stranding diskVS is driven with the aid of a motor MO3 via a toothed belt ZR2. In thisway, the stranding disk VS is set rotating synchronously with thestorage element SD. The stranding disk VS has a series of holes in themanner of a perforated ring GL2, in each of which the strandingelements, here optical cables BA1 to BAn, are guided individually. Afterleaving the storage element SD, the optical cables pass to a strandingnipple VN that rotates in a direction RR. In this stranding nipple VN,the optical cables, that is to say expressed in general terms thestranding elements, are combined into a bundle VB and, in the haul-offdirection AR, may be fed to further processing equipment not illustratedhere, such as a holding-spiral spinner. The stranded product produced inthis way is finally gripped with the aid of a haul-off device RA2, inparticular a caterpillar-belt haul-off, which effects the actual forwardtransport of the stranding elements over the storage element SD. Thestranded product transported forward in this way is finally wound uponto a supply coil AT or a plate and kept stored there.

During the oscillating rotational movement of the storage element SD, amaximum number of wraps of the stranding elements is alternately woundaround it in a helix and then filled again only with stranding elementsrunning parallel to its longitudinal extent. As a result, the strandingelements, here the optical cables BA1 to BAn, are fed with differenthaul-off speeds to the input side of the SZ stranding device SZV. Thesespeed fluctuations are advantageously compensated for with the aid ofthe loop accumulator SL according to the invention. In particular, theloop accumulator SL can enable decoupling to be achieved between theunwinding operation from the storage device, such as VT, of therespective stranding element, such as BA1, and the stranding operationof the latter.

By means of continuous monitoring and evaluation of the loop geometryduring the unwinding operation, it is therefore possible to derive acontrol criterion for controlling or regulating the outward transportspeed of the cable on its running path AW2. For this purpose, thecontrol device SE, in addition to or irrespective of regulating therotational speed of the supply coil VT via the control line SL1, may, ifappropriate, also activate the haul-off device RA2 on the output side ofthe following stranding device SZV via a corresponding, further controlline (which, for reasons of clarity, has been left out of FIG. 2 here).

In addition to or irrespective of the regulation of the speed of thestorage device for the respective telecommunication cable element, itmay possibly also be expedient to regulate the speed of the haul-offdevice RA1 which is arranged downstream of the storage device VT. Thisis particularly advantageous if a storage plate is used for the storagedevice VT. In this case, a constant torque is expediently set for theplate.

FIG. 3 shows, in schematic form, a perspective illustration of a plateTE of this type as a storage device for the optical cable BA1. The plateTE is constructed like a circular disk. With the aid of a bearing LG atits center, it is suspended such that it can rotate in a direction R3,about the axis of rotation ZA which is illustrated dash-dotted and whichruns through its center, as a surface normal, essentially perpendicularto its bearing plane. The plate TE is physically suspended in such a waythat its storage area forms essentially a horizontal storage plane TSfor the optical waveguide cable BA1. The individual turns or loops ofthe optical waveguide cable BA1 are laid down in the form of atorus-like arrangement on the top of the plate TE as a winding pack,that is to say the optical waveguide cable BA1 is stored in a torus-likestorage area of the plate TE with the aid of a large number ofapproximately circular turns. The torus-like storage area AB for theoptical waveguide cable BA1 is bounded on the outside by an outer,circularly annular plate rim AR. This outer plate rim projects upward atright angles to the horizontal bearing plane TS of the plate TE. As aresult, individual turns of the optical waveguide cable BA1 can beprevented from falling off the plate TE.

In a manner corresponding to this, the storage area AB is boundedradially inward by an inner, circularly annular plate rim IR, whichlikewise projects upward at right angles to the storage plane. In thisway, the laterally enclosed, ring-like or torus-like storage area AB isformed between the inner and outer plate rims IR, AR.

In order to unwind the cable BA1 from the plate TE, the cable BA1 istaken out of the plate TE so as to be freely mobile and loose, in such away that a sag DH is established for it. For this purpose, in FIG. 3,the cable is lifted off the winding pack at the circumferential locationAO and led out upward to a physically remote guide device which isplaced higher, in particular a deflection roller UR. The deflectionroller UR is roatably mounted in a bearing LA1. As a result of theinherent weight of the cable BA1, a specific sag DH is automaticallyestablished for said cable between its lifting location AO on the top ofthe plate TE and the deflection roller UR. The plate TE is set rotatingwith the aid of a drive device MO4, in particular a motor. This isindicated with the aid of an action arrow WP2. In this case, a largelyconstant torque or a fixed rotational speed, in particular, is set forthe motor MO4. In order to haul the cable out of the plate TE, ahaul-off device RA3, in particular a belt haul-off or a caterpillar-belthaul-off is arranged downstream of the rotatably mounted deflectionroller UR.

Downstream of the haul-off device RA3, the cable BA1 is led around, withthe aid of one or more deflection rollers RO1 to RO4, to form a loop SL*in a manner similar to the loop SL of FIG. 1. This loop SL* hangs downfreely. It is preferably designed like a circular ring. Its direction ofcurvature is preferably selected to be the same as the bending directionof the cable on the plate TE. In particular, its external diameter isselected to a first approximation to be approximately equal to thediameter of the respective cable turn on the plate TE. In order to formthe loop SL* with the aid of deflection rollers RO1* to RO4*, the cable,coming from its original haul-off path from the haul-off device RA3,which runs rectilinearly here, is deflected through about 360°. Afterpassing through the loop SL*, the cable is transported forward, againessentially rectilinearly, in the haul-off transport direction AZ.

In order to be able to transport the cable BA1 forward largely with alow tensile stress along its axial longitudinal extent downstream of thehaul-off device RA3, a specific loop diameter is preferably predefined.The haul-off speed of the haul-off device RA3 is then continuouslyadjusted during the unwinding process in such a way that the result isapproximately always about the same loop diameter from the first to thelast turn WI of the cable BA1 to be unwound. For this purpose, therespectively current external diameter of the loop SL* of the cable BA1is measured with the aid of the measuring sensor US and, as a controlcriterion, is transmitted via the measuring line ML to the controldevice SE for controlling the haul-off speed of the haul-off device RA3.The control device SE advises the haul-off device RA3 appropriately viaa control line SL2. The fact that the haul-off device RA3 is controlledor regulated in such a way that, from the first to the last unwoundcable turn, that is to say for all the cable turns of the winding pack,essentially the same geometric shape and loop size, in particular thesame external diameter of the loop SL*, is established, means that it ispossible to feed the cable downstream of the haul-off device RA3 largelywith a low tensile stress to further production devices, although thesehave been left out of FIG. 3 here for the purpose of clarity of thedrawing.

At the same time, it can also be ensured that the cable remains largelyfree of compression. As a result, the length ratio previously set in adefined way during the manufacturing process between the cable sheathand optical waveguide for the optical waveguide cable can also belargely maintained after said cable has been unwound from the storagedevice. In particular, it can largely be ensured that any excess lengthachieved during the manufacturing process of the respective opticalwaveguide with respect to the cable sheath surrounding it is notundesirably reduced or even completely eliminated by the action ofunwinding the cable. As a result of the free mobility of the loop SL*,its diameter can always be set freely, that is to say unimpededly. As aresult, the situation is largely avoided in which the cable is notstressed by being flexed in an impermissible way during the unwindingoperation by excessively small bending radii. For the fully circularlyannular loop that hangs down, it is expedient if a bending radius ismaintained which corresponds to at least 30 times the cable diameter, inparticular between 40 and 50 times the cable diameter. Since thecircularly annular loop can be established freely and hangs down freely,and its loop geometry can be measured without contact, there is nomechanism which acts in an undesirable way on the cable during itsremoval from the storage device and its unwinding movement. As a result,the cable can be unwound from its storage device largely withoutfriction. In addition, the measuring system remains largely free ofwear. In addition, the measurement and control system for controllingthe transport speed of the cable remains largely free of externalinertia, that is to say the result is short reaction times for themeasurement and control system, so that high measurement dynamics can beachieved. Since the measurement of the sag is preferably carried outwithout contact, the measurement is, moreover, advantageouslyindependent of cable properties, such as cable diameter, cable weight,cable stiffness or cable surface.

As a result of measuring the loop geometry, it is at the same timeadvantageously made possible to detect faults in the unwinding operationof the cable as well, such as disruptive thick points or otherinhomogeneities in the geometric shape of the cable. If, for example,the distance of the loop, such as SL* or SL, from the measuring sensorUS becomes too large, that is to say if it exceeds an upper limitingvalue, it can be concluded in particular that the cable has becomecaught at some point on its plate or its supply coil or in a followingfurther processing device. The production line can then advantageouslybe switched off immediately, if appropriate. If no distance at allbetween cable and measuring sensor is measured, then it can beconcluded, in particular, that the cable has been unwound completelyfrom the plate.

Within the context of the invention, the term optical waveguide cable ispreferably understood to mean an optical cable in whose cable sheatheither only a single optical waveguide (hollow cable) or else a largenumber of optical waveguides can be accommodated loosely, that is to sayso as to be essentially freely mobile, or with play (bundle tube). Forthe cable sheath, an extruded plastic can preferably be used. Theunwinding method according to the invention can be used, in a mannerwhich is equally advantageous, for an individual optical waveguide,optical waveguide ribbon or other optical transmission elements.

In addition, the unwinding principle according to the invention is alsosuitable for unwinding other mechanically sensitive, in particulartensile-stress-sensitive, wound products in cable technology, such aselectrical cables, winding threads, retaining spirals or the like.

In addition to the arrangements, presented in FIGS. 1 to 3, of storagedevice, guide device and loop accumulator, other constructions are ofcourse also possible, provided it is ensured that at least one loop ofthe telecommunication cable element to be unwound can be paid out so asto be freely mobile.

The invention is above all distinguished by the fact that haul-offregulation is still possible even when an elongate product with a highinherent stiffness is to be unwound. Speed fluctuations arising fromfurther processing machines, such as an SZ stranding machine, canadvantageously be compensated for by the loop accumulator. The loopaccumulator permits the unwinding movement to be decoupled fromsubsequent further processing processes. In particular, high unwindingspeeds are made possible. The observation of the loop geometryadvantageously permits rapid response of the regulating or controlsystem for the outward transport movement of the elongate product.

What is claimed is:
 1. A method of unwinding an elongatetelecommunication cable element from a storage device, on which thetelecommunication cable element is stored with a large number of turns,characterized in that the elongate telecommunication cable element istransported away in an axial direction from the storage device in such away that at least one loop of about 360 degrees is formed at at leastone longitudinal point on a longitudinal outward transport path of thetelecommunication cable element, whereby changes in the geometric shapeof the loop are registered by means of non-contact measurement, saidchanges in the geometric shape are used to derive at least one controlcriterion for an outward transport movement of the elongatetelecommunication cable element.
 2. The method as claimed in claim 1,wherein the loop is paid out essentially as a circular ring.
 3. Themethod as claimed in claim 1, wherein the loop is paid out so as to beas freely mobile as possible.
 4. The method as claimed in claim 1,wherein the loop is paid out with the same direction of curvature asthat with which the telecommunication cable element was wound onto thestorage device.
 5. The method as claimed in claim 1, wherein thediameter of the loop is selected to be approximately equal to thewinding diameter of the turns of the telecommunication cable element. 6.The method as claimed in claim 1, wherein the outward transport movementof the telecommunication cable element is carried out in such a way thata predefined diameter of the loop is always kept largely constant. 7.The method as claimed in claim 1, wherein the loop is paid outvertically.
 8. The method as claimed in claim 1, wherein the loop ispaid out horizontally.
 9. The method as claimed in claim 1, wherein, asthe control criterion, the change in the diameter of the loop ismeasured.
 10. The method as claimed in claim 1, wherein, as the controlcriterion, the change in the distance of the loop from a non-contactmeasuring sensor is measured.
 11. The method as claimed in claim 1,wherein the storage device is driven in rotation.
 12. The method as inclaim 11, wherein said rotation of said storage device comprises a speedof rotation, said speed of rotation of said storage device beingcontrolled or regulated on the basis of the control criterion.
 13. Themethod as claimed in claim 1, wherein the haul-off speed of thetelecommunications cable element is controlled or regulated on the basisof the control criterion.
 14. The method as claimed in claim 1, whereinthe telecommunication cable element is transported essentiallyrectilinearly away from the storage device.
 15. The method as claimed inclaim 1, wherein, after passing through the loop, the telecommunicationcable element is fed to a further processing device.
 16. The method asclaimed in claim 1, wherein the diameter of the loop is selected to besufficiently large that changes in the haul-off speed of thetelecommunication cable element, which are caused by at least oneprocessing device downstream of the loop, as viewed in its outwardtransport direction, are largely compensated for in terms of length. 17.The method as claimed in claim 1, wherein the telecommunication cableelement is pushed onto the loop with the aid of at least one auxiliaryhaul-off.
 18. The method as claimed in claim 17, wherein the auxiliaryhaul-off between the storage device and the loop is operated in such away that, downstream of the auxiliary haul-off, the telecommunicationcable element is transported forward largely with a low tensile stress.19. The method as in claim 1, wherein said telecommunication cableelement comprises an optical transmission element.